While social communication deficits are considered the hallmark of Autism Spectrum Disorders (ASD), there is increasing evidence that sensorimotor deficits are also common in individuals with ASD diagnoses. A large body of research suggests that brain systems for execution and observation of actions are involved in higher social cognitive processes, including intention understanding and empathy, yet research has not yet clarified the extent to which motor deficits, such as imitation ability and motor planning, are central to ASD nor whether social and motor deficits are related neurobiologically in ASD. Understanding the neurobiological basis for ASD is crucial for developing effective therapies. However, researching the neurobiology of ASD is complicated by the heterogeneity of ASD; patients vary in symptomology- e.g., some individuals may show extensive impairment in motor functioning while others may not. Our study is designed to accommodate and understand the relationship between symptomalogical variation in ASD along the dimensions of both social and motor impairments. We aim to show how variations in social and motor symptoms in ASD relate to functioning in social and motor brain networks and functional connectivity between them. We propose to conduct functional MRI studies that compare 120 children on two continua of symptomology: (1) degree of social impairment (as measured by the SRS-2 and NEPSY-II), and (2) degree of motor impairment (as measured by the MABC-2 and Praxis Test). To ensure a range of impairment along these continua, children with ASD and children with Developmental Coordination Disorder (DCD, sometimes called dyspraxia) as well as typically developing (TD) children will participate in the study. The ASD group will range in motor impairment but should show high social impairment, while the DCD group will range in social impairment (generally lower than ASD) but high in motor impairment. Our fMRI tasks are likewise selected to range on a continuum from purely motor tasks to social processing tasks, beginning with motor (hand) execution and imitation tasks and progressing to tasks that incorporate increasing dimensions of social processing (e.g., non-emotional face imitation, emotional face imitation, intention understanding). By testing individuals who represent a continuum of social and motor deficits along a continuum of social and motor tasks we will be able to isolate and understand, in ASD, interactions between: (1) social and sensorimotor symptomologies; (2) activity in social and motor brain networks; and (3) functional connectivity between social and motor brain networks. This understanding will be crucial for developing individualized treatments for ASD. To our knowledge, no fMRI study has examined children with ASD across these multiple continua, nor directly compared them to children with DCD. In addition to contributing to our understanding of ASD, this study will better elucidate the neural mechanisms underlying DCD, which affects 6-13% of school-aged children.